Vitamin K2 as MK4 supports bone density and reduces fracture risk.  It has been studied for over 30 years including 25 clinical trials involving more than 7000 people.  A clear dosage of 45mg/day (15mgX3 with food) was used.  The only contraindication is warfarin/coumadin.  Here is a link to the clinical trials:

NBI MK4 Osteo Research Updated 2023 (nbihealth.com)

Here is a link to a free ebook about growing stronger bones by Dr. John Neustadt:
Discover More - NBI (nbihealth.com)